Process monitoring device for sample processing apparatus and control method of sample processing apparatus

ABSTRACT

A plasma processing method for processing a sample by using plasma on a lot unit basis, including: detecting plural kinds of information as monitor data relating to a processing state of the sample, using a plurality of sensors; selecting a detection time range of the monitor data thus detected; converting the monitor data within the selected detection time range into a converted signal; predicting a pattern shape of the sample based on the converted signal; calculating a correction quantity of a processing parameter, for decreasing a deviation between the predicted pattern shape and a standard value; and converting the correction quantity of a processing parameter obtained by the calculating operation when a kind of a next sample of a next lot is different from the sample, thereby to use a converted correction quantity of the processing parameter for a processing of the next sample.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. application Ser. No. 11/356,099, filedFeb. 17, 2006, which is a continuation of U.S. application Ser. No.10/987,121, filed Nov. 15, 2004 (now U.S. Pat. No. 7,058,467), which isa continuation of U.S. application Ser. No. 09/945,691, filed Sep. 5,2001 (now U.S. Pat. No. 6,879,867). This application relates to andclaims priority from Japanese Patent Application No. 2001-060995, filedon Mar. 5, 2001. The entirety of the contents and subject matter of allof the above is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a process monitoring device for sampleprocessing apparatus and a control method of sample processingapparatus. In particular, the present invention relates to a processmonitoring device for vacuum processing apparatus suitable for finepatterning of semiconductor devices and a control method ofsemiconductor device manufacturing apparatus utilizing the processmonitoring device.

Year after year, critical dimensions of semiconductor devices arebecoming finer and finer, and demands on dimension precision ofpatterning are becoming more and more strict. On the other hand, in asemiconductor manufacturing apparatus for patterning a semiconductorwafer physically or chemically by using heat and plasma, reactionproducts produced by a chemical reaction within the apparatus sticks toan internal wall of the apparatus and remains. Thus the reactionproducts often change the processing state of the wafer as processinggoes on. Therefore, there is a problem that as the wafer processing isconducted on a large number of wafers the patterned shape of thesemiconductor device gradually changes and the performance is degraded.In order to improve the situation, there are some countermeasures suchas cleaning substances sticking to an internal wall of a chamber byusing plasma and raising the temperature of the chamber wall to makesubstances hardly stick. In most cases, however, these countermeasuresare not complete. Eventually, the patterned shape of the semiconductordevices gradually changes. Before the patterned shape changes so as topose a problem, therefore, replacement or cleaning of parts of themanufacturing apparatus is conducted. Besides the deposited film,various variations of the apparatus state relate to variations of thewafer patterned shape. Therefore, there has been devised a contrivancesuch as detecting a change of the processing state within thesemiconductor manufacturing apparatus, feeding back a result ofdetection to an input of a plasma processing apparatus, and keeping theprocessing state constant.

A method for monitoring such a variation of plasma processing isdisclosed in, for example, JP-A-10-125660. In the disclosed example,there is shown a method of predicting the apparatus performance anddiagnosing the plasma state by using model equations of relationsbetween the plasma processing characteristic and electric signals of theapparatus. As its method, there is disclosed a method of deriving modelequations representing relations between three electric signals and theplasma processing characteristic of the apparatus by using a multipleregression analysis. Another example is disclosed in JP-A-11-87323. Inthis disclosed example, there is shown a method of applying a typicaldetection system having a multiplicity of existing detectors attachedthereto to a plasma processing apparatus and monitoring the apparatusstate on the basis of the correlation signal of the detected signal. Asa method for generating the correlation signal, model equations usingratios of six electric signals are disclosed. Another disclosure exampleis found in U.S. Pat. No. 5,658,423. In this disclosure example, thereis shown a method of taking in light or a large number of a massspectrometer, generating a correlation signal, and monitoring theapparatus state. As a method for generating this correlation signal,there is disclosed a method of using a principal component analysis.

SUMMARY OF THE INVENTION

In the method described in JP-A-10-125660, however, model equationsrepresenting relations between three electric signals and a processingcharacteristic are derived by using a multiple regression analysis on amap of a multi-dimensional space having a large number of processingconditions as axes. For thus measuring the processing characteristic ona vast map, an extremely large number of wafers are needed and itspractical use is difficult. In addition, if a processing condition thathas not been considered at the time of measurement changes, the derivedmodel equations cannot be used. Furthermore, for introducing aninfluence of an internal condition that is difficult to observe and thatposes a problem in practical use, such as a deposited film within thechamber, into the model equations, a further enormous number ofprocessing characteristic acquisition experiments are needed. The methoddescribed in JP-A-11-87323 is a typical well-known method in which acorrelation signal obtained from a multiplicity of detected signalssupplied from a multiplicity of detection sections is used fordiagnosis. However, the disclosed method for obtaining the correlationis also a conventional technique in which ratios of several signals arederived. It is thus difficult to find a concrete implementation sectionof a system that accurately monitors the state of a plasma processingapparatus, which assumes various states according to many variationcauses.

Unlike this, U.S. Pat. No. 5,658,423 provides a method of monitoringvarious plasma states by conducting a principal ingredient analysis on alarge quantity of data obtained by monitoring an apparatus and graspinga variation of the apparatus state. However, a further contrivance isneeded for finding an effective implementation method in an actualplasma processing apparatus, which processes wafers having variousdevice structures under various conditions, from this disclosed example.Especially in these known examples, there is not taken intoconsideration the fact that processing of even one wafer is typicallyconducted under a combination of some processing conditions andinfluences of respective processing steps on the working precisiondiffer. Even if the processing conditions are constant, influences onthe patterned shape differ according to whether the processing isconducted in the former half of the processing time or in the latterhalf of the processing time. The performance of the future semiconductordevices is sensitive even to an extremely minute change of the patternedshape. For monitoring such a minute change of the patterned shape andeffecting control, a monitoring method of concrete processing with dueregard to the time sequence of the processing is dispensable.

An object of the present invention is to provide a process monitoringdevice, a control method of a sample processing apparatus, and a samplemanufacturing method that are capable of coping with various processingstates of the sample processing apparatus and that can be easilyoperated.

Another object of the present invention is to provide a processmonitoring device, a control method of a sample processing apparatus,and a sample manufacturing method that are capable of monitoring theprocessing states of the sample processing apparatus, monitoring thechange of the processing state accurately and easily, and controllingthe processing conditions.

In accordance with a first aspect of the present invention, a processmonitoring device includes: a monitor data acquisition section foracquiring a multiplicity of monitor data relating to a processing stateof one sample in a processing apparatus, via sensors; a data selectionsection for selecting monitor data belonging to an arbitrary processingdivision included in a multiplicity of processing divisions for thesample, from among the multiplicity of monitor data; a monitoring signalgeneration section for generating monitoring signals based on themonitor data belonging to the arbitrary processing division selected bythe data selection section; and a display setting controller fordisplaying a multiplicity of the monitoring signals obtained withrespect to samples processed in the processing apparatus, on a displaysection in a time series manner.

In accordance with another aspect of the present invention, a processmonitoring device includes: a monitor data acquisition section foracquiring a multiplicity of monitor data relating to a processing stateof one sample in a processing apparatus, via sensors; a data selectionsection for selecting monitor data belonging to an arbitrary processingdivision included in a multiplicity of processing divisions for thesample, from among the multiplicity of monitor data; a monitoring signalgeneration section for generating monitoring signals based on themonitor data belonging to the arbitrary processing division selected bythe data selection section; a display setting controller for displayinga multiplicity of the monitoring signals obtained with respect tosamples processed in the processing apparatus, on a display section in atime series manner; and a display switchover section for switching overthe display according to a use situation of the processing apparatus.

In accordance with still another aspect of the present invention, aprocess monitoring device includes: a monitor data acquisition sectionfor acquiring a multiplicity of monitor data relating to a processingstate of one sample in a processing apparatus, via sensors; a monitoringsignal generation section for extracting fewer monitoring signals thanthe number of monitored data, from among the multiplicity of monitordata by working the monitor data; and a display setting controller fordisplaying a multiplicity of the monitoring signals obtained withrespect to samples processed in the processing apparatus, on a displaysection in a time series manner.

According to the present invention, there is provided a section formonitoring the processing state of a sample processing apparatus havinga various complicated states due to processing conditions and theaccumulated number of processed samples, and acquiring apparatusmonitoring signals used to monitor the apparatus, from the variousprocessing sequences. As a result, it is possible to provide a processmonitoring device and its display method, a control method of a sampleprocessing apparatus, and a semiconductor device manufacturing methodthat can be easily operated.

Furthermore, according to the present invention, monitor data areacquired from the plasma device by using sensors, and apparatusmonitoring signals are generated from data of the most important sampleprocessing division concerning the sample processing performance. As aresult, it is possible to monitor the change of the processing stateaccurately and easily, and control the processing conditions.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a diagram showing a general configuration of a sampleprocessing apparatus according to a first embodiment of the presentinvention;

FIG. 2 is a diagram showing an example of a display screen of a displaysection in the sample processing apparatus of FIG. 1;

FIG. 3 is a diagram showing a configuration example of a processingsystem of a display setting controller for carrying out the display ofFIG. 2;

FIG. 4 is a diagram showing an embodiment of a flow of data processingof FIG. 3;

FIG. 5 is a diagram showing an example of a monitoring type selectionwindow in a sample processing apparatus of FIG. 1;

FIG. 6 is a diagram showing an example of an operation flow of a displaysetting controller in case of FIG. 5;

FIG. 7 is a diagram showing another example of a display sample numbersetting window in the sample processing apparatus of FIG. 1;

FIG. 8 is a diagram showing an example of an operation flow of a displaysetting controller in case of FIG. 7;

FIG. 9 is a diagram showing another example of a display sample numbersetting window in the sample processing apparatus of FIG. 1;

FIG. 10 is a diagram showing an example of an operation flow in adisplay setting controller of FIG. 9;

FIG. 11 is a diagram showing another example of a window and a displaysetting controller in a display section of the present invention;

FIG. 12 is a diagram showing another example of a window and a displaysetting controller in a display section of the present invention;

FIG. 13 is a diagram showing another example of a window and a displaysetting controller in a display section of the present invention;

FIG. 14 is a diagram showing another example of a window and a displaysetting controller in a display section of the present invention;

FIG. 15 is a diagram showing another example of a window and a displaysetting controller in a display section of the present invention;

FIG. 16 is a diagram showing another example of a window and a displaysetting controller in a display section of the present invention;

FIG. 17 is a diagram showing a configuration of a data processing systemof a display setting controller for carrying out display of FIG. 16;

FIG. 18 is a diagram showing an example of a graph showing a comparisonof two signals in FIG. 17;

FIG. 19 is a diagram showing an example of data of comparison conductedfrom lot to lot in the embodiment of FIG. 16;

FIG. 20 is a diagram showing another embodiment of a sample processingapparatus of the present invention;

FIG. 21 is a diagram showing another embodiment of a display screen of adisplay section in a sample processing apparatus of the presentinvention;

FIG. 22 is a diagram showing another example of a display screen of adisplay section in a sample processing apparatus of the presentinvention;

FIG. 23 is a diagram showing another embodiment of a display section ina sample processing apparatus of the present invention;

FIG. 24 is a diagram showing another embodiment of a display section ina sample processing apparatus of the present invention;

FIG. 25 is a diagram showing another embodiment of a display section ina sample processing apparatus of the present invention;

FIG. 26 is a diagram showing another embodiment of a display section ina sample processing apparatus of the present invention;

FIG. 27 is a diagram showing another embodiment of a display section ina sample processing apparatus of the present invention;

FIG. 28 is a diagram showing another embodiment of a display section ina sample processing apparatus of the present invention;

FIG. 29 is a diagram showing another embodiment of a display section ina sample processing apparatus of the present invention; and

FIGS. 30, 31, 32 and 33 are diagrams showing display screen examples inother embodiments of a display section in a sample processing apparatusof the present invention.

DESCRIPTION OF THE EMBODIMENTS

Hereafter, embodiments of the present invention will be described byreferring to the drawing. In the ensuing description, components havingthe same function are denoted by like numerals, and duplicateddescription thereof will be omitted.

In FIG. 1, a first embodiment of the present invention is shown. FIG. 1is a diagram showing a configuration of a sample processing apparatushaving sensors and a display device according to a first embodiment ofthe present invention. Numeral 1 denotes a sample processing apparatussuch as a semiconductor manufacturing apparatus or an LCD manufacturingapparatus. Herein, the sample processing apparatus 1 will be describedas a semiconductor manufacturing apparatus that processes silicon wafersfor manufacturing semiconductor devices as samples. The sampleprocessing apparatus 1 includes a vacuum receptacle, a discharge sectionfor forming a plasma generation section therein, and a processingsection having electrodes for disposing a sample to be processed, suchas a wafer, in the vacuum receptacle. Processing gas from a gas supplyapparatus is supplied into the vacuum receptacle of the sampleprocessing apparatus 1. The inside of the vacuum receptacle is evacuatedby an evacuation apparatus so as to be decreased in pressure to apredetermined pressure. A high frequency power supply is connected tothe electrodes.

In the sample processing apparatus 1 having the above describedconfiguration, a wafer (sample) is carried in and placed on theelectrodes. And processing gas is supplied to the inside of the vacuumreceptacle by the gas supply apparatus. The processing gas becomesplasma by action of an electric field. The sample is subjected toprocessing, such as plasma etching, by the processing gas and plasma.The gas is evacuated later by the evacuation apparatus. Processing ofthe sample in the sample processing apparatus 1 is controlled by acontroller 3.

In the sample processing apparatus 1, there are installed a multiplicityof sensors 2 for detecting and acquiring information concerning variousprocessing states in the sample processing apparatus as monitor data.The sensors 2 monitor the processing states of the sample and theprocessing environment of the sample (hereafter simply abbreviated tothe processing states of the sample) in the sample processing apparatus.At fixed or arbitrary time intervals, the sensors 2 acquire the monitordata. To be concrete, information concerning the processing gas suppliedto the processing apparatus, and information concerning the pressurewithin the processing apparatus, the state of plasma generated withinthe processing apparatus, and processing working of the sample areincluded.

The sensors 2 may include a light detection section such as an opticalspectrometer or a monochromator. The sensors 2 may include an electricsignal detector such as a voltage detector, a current detector, or animpedance monitoring section. The sensors 2 may include a pressuredetector of the inside of the apparatus. The sensors 2 may include aprocessing gas flow detector, or a position detector or a temperaturedetector of an operational portion of the apparatus, The sensors 2 mayinclude a gas composition detector, such as a mass spectrometer, of theinside of the apparatus.

In order to grasp the complicated processing states within theprocessing apparatus, however, it is desirable to acquire as many anddiverse monitor data as possible. In other words, spectra data obtainedby dissolving light generated by plasma according to the wavelength, andspectra data obtained by dissolving an electric signal according to thefrequency are optimum as monitor data.

Monitor data acquired by the sensors 2 are sent to a data selectionsection 4. For example, the sensor 2 acquires a spectrum of lightgenerated in the processing apparatus once per second and sends it tothe data selection section 4.

The data selection section 4 selects a portion to be used for apparatusmonitoring from the sent monitor data. To be the simplest, the dataselection section 4 may select all monitor data. The monitor dataselected by the data selection section 4 are sent to an apparatusmonitoring signal generation section 5. The apparatus monitoring signalgeneration section 5 generates apparatus monitoring signals according tomonitoring types from the received monitor data, and sends them to anoutput data buffer 6. The monitoring type means a subject to bemonitored with respect to the sample processing, such as the patternedshape of the sample, the state of a deposition film within theprocessing apparatus, the degrees of wear of components of theprocessing apparatus, a change of the processing state obtained fromsample to sample by comparison among a multiplicity of samples, and achange of the processing state obtained from lot to lot by comparisonamong a multiplicity of lots.

The output data buffer 6 holds as many apparatus monitoring signals asrequired, and sends a multiplicity of apparatus monitoring signals to adisplay section 7. The display section 7 displays the sent apparatusmonitoring signals on a display screen, and has a display settingcontroller 8. The display setting controller 8 has a function of settinga selection method in the data selection section 4, a monitoring type inthe apparatus monitoring signal generation section 5, and the number ofoutputs in the output data buffer 6. The output data buffer 6 may beincorporated into the display section 7. The display setting controller8 need not necessarily be attached to the display section 7, but mayexist independently.

FIG. 2 shows an example of a display screen of the display section 7 inthe sample processing apparatus 1 of FIG. 1. The display screen of thedisplay section 7 has a function of serving as an input/output sectionfor the display section 7 and the display setting controller 8. Displayin a window 22 is controlled by the display setting controller 8.

In FIG. 2, the window 22 of the display section 7 displays the variationof the processing state from wafer to wafer. The window 22 displays agraph with, for example, the abscissa indicating wafers finished inprocessing and arranged in a time series and the ordinate indicating theapparatus monitoring signal plotted for each wafer. A description 21 ofan event that has occurred in the apparatus may be added to the window22. As for this event, an event that has occurred in the processingapparatus currently under processing, and an event that occurred in asemiconductor manufacturing apparatus that processed displayed wafers inthe past may be acquired by a LAN or the like and displayed.

A button 24 displays a monitoring type of the apparatus monitoringsignals currently displayed in the window 22. In addition, the button 24may serve as a command button for opening a monitoring type settingwindow. In the same way, a button 25 displays the number of wafersdisplayed in the window 22. In addition, the button 25 is also a commandbutton for opening a display sample number setting window. A button 26displays a device type, i.e., a sample kind displayed in the window 22.In addition, the button 26 is also a command button for opening a devicetype setting window. A button 27 displays a sample processing divisionfor generating the apparatus monitoring signals to be displayed in thewindow 22. In addition, the button 27 is also a command button thatopens a window for selecting the sample processing division.

FIG. 3 shows a configuration example of a processing system of thedisplay setting controller 8 for carrying out the display of FIG. 2.FIG. 4 shows an embodiment of a flow of the data processing.

In semiconductor manufacturing apparatuses, sampling processing isconducted under a combination of a multiplicity of processing conditionsin many cases. Herein, a portion corresponding to each processingcondition in the sample processing is referred to as sample processingdivision. The sample processing divisions are for example, a processingstep of the sample, a sample unit, a lot unit, idle time of the sampleprocessing time, and so on. The sample processing division may bedivided further finely irrespective of partitions of the processingcondition, or may be divided more roughly, for example, into the formerhalf and latter half of the processing. For example, when the monitoringtype is the sample patterned shape, the final sample patterned shape isnot influenced evenly by all sample processing divisions, but there is asample processing division to be monitored preponderantly. Therefore,monitor data acquired by the sensors 2 are sent to the data selectionsection 4 (S400 to S402 in FIG. 4).

In the case of this embodiment, the data selection section 4 includesonly a sample processing division selection 9. By using a sampleprocessing division selection button 10, a sample processing division ofmonitor data to be output can be selected. Selected monitor data is sentto the apparatus monitoring signal generation section 5 (S404).Apparatus monitoring signals of a kind selected by a monitoring typesetting button 11 are generated by the apparatus monitoring signalgeneration section 5 (S406), and sent to the output data buffer 6(S408). Typically, in the selected sample processing division, a largenumber of monitor data are acquired. As a result, a large number of dataconcerning the change of the apparatus monitoring signals with time aregenerated. In the case where the change of the processing state withtime is to be monitored, the change of the processing state with time issent to the output data buffer as it is. In the case where the change ofthe processing state from sample to sample is to be monitored,processing of averaging the apparatus monitoring signals for each sampleand so on is conducted, and then a resultant signal is sent to theoutput data buffer 6. The output data buffer 6 sends apparatusmonitoring signals corresponding to as many samples as the numberspecified by using a display sample number setting button 12 to adisplay device selection section 13 (S410). Only apparatus monitoringsignals of samples of a kind specified by using a display deviceselection button 14 are sent to the display section 7, and displayed(S412).

In FIGS. 5 and 6, another example of the window and the display settingcontroller 8 of the display section 7 is shown. FIG. 5 shows an exampleof a monitoring type selection window. FIG. 6 shows an example of anoperation flow of the display setting controller 8.

If the button 24 is pressed, then the monitoring type selection windowis displayed (S602 to S606). And a monitoring type can be selected byusing a menu 28 (S608 to S612). As for selection items of the menu 28,for example, “comprehensive level 1” is a monitoring type for displayinga rough processing state of the apparatus. “Comprehensive level 2” is amonitoring type of the processing state for monitoring a finer variationof the processing state. “Comprehensive level 3” is a monitoring typefor monitoring a further finer variation. Besides, there may be an itemof “processing performance” relating to the working dimension precisionand patterned speed. There may be an item of “part wear” for indicatingthe degree of wear of parts in the apparatus. The check box 28 may beformed so that a multiplicity of kinds may be selected. In the casewhere a multiplicity of kinds have been selected, apparatus monitoringsignals of a multiplicity of kinds are displayed in the window 22.

In FIGS. 7 and 8, another example of the window and the display settingcontroller 8 of the display section 7 is shown. FIG. 7 shows a displaysample number setting window. FIG. 8 shows an example of an operationflow of the display setting controller 8.

The display sample number setting window is displayed by pressing thedisplay sample number setting button 25 (S802 to S806). In the case ofdisplay conducted from sample to sample as in the window 22, the numberof display samples is set by using an input section 29. In the case ofdisplay conducted from lot to lot as in a window 23 described later, thenumber of display lots is set by using the input section 29 (S808 toS814).

In FIGS. 9 and 10, another example of the window and the display settingcontroller 8 of the display section 7 is shown. FIG. 9 shows an exampleof a device type selection window. FIG. 10 shows an example of anoperation flow of the display setting controller 8.

If the button 26 is pressed, then the device selection window isdisplayed (S1002 to S1006). A multiplicity of device kinds of samplescan be selected by using check boxes 31 (S1008 to S1012). On devicelabels 32 corresponding to the check boxes 31, device kinds are listed.For example, it is now assumed that a device name is “T12345F” and “T”and “F” in the device name have meanings concerning the devicestructure. In this case, it is desirable to be able to select not only“T12345F” as the display device name but also all device names beginningwith “T” or all device names ending with “F”. On the device labels 32,it is also made possible to select all of the same devices as the samplefinished in processing immediately before. When there are a multiplicityof kinds of recipes, i.e., combinations of processing conditions for thesame device, it is also permissible to recognize them as respectivelyseparate devices and allow device selection. Or a separate recipeselection window may also be prepared. If selection of device kinds tobe displayed is finished and an end button 30 is pressed, then theselected device kind is decided and the device selection window isfinished (S1014).

In FIG. 11, another example of the window and the display settingcontroller 8 of the display section 7 is shown. FIG. 11 shows an exampleof a sample processing division selection window. By using check boxes33, a multiplicity of sample processing divisions to be used forgenerating the apparatus monitoring signals can be selected. Operationof the display setting controller 8 is the same as that of FIG. 10. Froma multiplicity of sample processing divisions, one apparatus monitoringsignal may be generated and displayed. Or a multiplicity of apparatusmonitoring signals may be generated and displayed. On sample processingdivision labels 34 corresponding to the check boxes 33, sampleprocessing division names are displayed. Since the sample processingdivision name required to generate the apparatus monitoring signaldiffers depending upon the monitoring type, it is desirable that thesample processing division labels 34 differ according to the monitoringtype selected by using the pull-down menu 28.

In FIG. 12, another example of the window and the display settingcontroller 8 of the display section 7 is shown. In this example, not apre-defined sample processing division, but an arbitrary processingdivision can be selected. By specifying a step start point 35 and a stepend point 35′ on a time axis 36, an arbitrary time range can beextracted as a sample processing division.

In FIG. 13, another example of the window and the display settingcontroller 8 of the display section 7 according to the present inventionis shown. A general operation sequence of this example is the same asthat of FIG. 3 except in that an automatic sample processing divisionselection section 15 is added. In this example, the user does notconduct selection on displayed sample processing divisions. Theautomatic sample processing division selection section 15 judges asample processing division that is optimum for a monitoring type set bythe monitoring type setting button 11, and sets operation of the sampleprocessing division selection 9. As for the processing steps selectedhere, some processing steps may be selected for one monitoring type.

In FIG. 14, another example of the window and the display settingcontroller 8 of the display section 7 according to the present inventionis shown. In this embodiment, data acquired by the sensors 2 are storedin a monitor data preservation section 16. Subsequently, a data loadsection 17 takes out as many data as a number selected by using adisplay sample number setting button 12, from the monitor datapreservation section 16, and sends the data to a device selectionsection 13. The device selection section 13 sends only monitor data ofsamples of kinds specified by using a device selection section 14 to asample processing division selection section 9. Thereupon, only monitordata specified by using a sample processing division selection button 10are sent to the apparatus monitoring signal generation section 5, andapparatus monitoring signals corresponding to the monitoring typesetting button 11 are displayed on the display section 7.

In FIG. 15, another example of the window and the display settingcontroller 8 of the display section 7 according to the present inventionis shown. In FIG. 14, monitor data of past processing are preserved. Inthe example of FIG. 15, only apparatus monitoring signals of past sampleprocessing are preserved in an apparatus monitoring signal database 20.A sample processing division selection section 60 acquires apparatusmonitoring signals of the past samples from the apparatus monitoringsignal database 20, and supplies the signals to the output data buffer6. In the case where there are a large quantity of data and the storagecapacity becomes enormous, this method has an advantage that thepreservation capacity can be reduced by storing only the apparatusmonitoring signals compressed in information.

In FIGS. 16 and 17, another example of the window and the displaysetting controller 8 of the display section 7 according to the presentinvention is shown. A window 23 of this example displays a variation ofthe processing state from lot to lot. For selecting display conductedfrom wafer to wafer or display conducted from lot to lot, the selectioncan be conducted by using, for example, a sample after sample displayselection button 28′ or a lot after lot display selection button 28′ inthe monitoring type selection window. The window 23 displays a graphwith, for example, the abscissa indicating lots finished in processingand arranged in a time series and the ordinate indicating the apparatusmonitoring signal plotted for each lot. In manufacturing semiconductordevices, samples are processed by taking a cluster of several samplescalled lot as the unit.

In the case of 8-inch wafers, a cluster of twenty-five wafers is one lotin many cases. However, the number of samples included in one lotdiffers according to circumstances. Cleaning of the internal wall of theapparatus is conducted between samples in some cases. However, specialcleaning processing is conducted between lots in some cases.Furthermore, in an idle time between lots, the temperature of each placein the processing chamber might change. Even in such a situation thatsamples are processed stably, therefore, the apparatus monitoring signaldoes not become a constant value. A certain variation pattern oftenrepeats from lot to lot. This variation pattern differs according to thedevice kind of samples. In such a case, the conventional monitoringmethod of only determining whether a signal exists in a certain constantrange is insufficient.

In the present invention, a variation pattern of a standard apparatusmonitoring signal obtained during processing of a pertinent device andacquired from the database is compared with a variation pattern of amonitored apparatus monitoring signal. The comparison data is displayedas an apparatus monitoring signal plotted from lot to lot. A lot thathas had an abnormality in processing can be easily found. Furthermore,it is more desirable that if a display portion of a lot is selected by amouse or the like apparatus monitoring signals of respective materialsin that lot are displayed. In this case, when a lot that is consideredto be abnormal is found, selecting a display portion of this lot causesprocessing states of samples belonging to the abnormal lot to bedisplayed in the window 22. A sample included in the abnormal lot andsubjected to abnormal processing can be easily found. Display in thewindow 23 can also be controlled by using buttons 24′, 25′, 26′ and 27′having functions similar to those of the window 22.

FIG. 17 shows a configuration of a data processing system of the displaysetting controller 8 for carrying out the display of FIG. 16. Monitordata acquired by sensors 2 are subject to selection conducted by a dataselection section 4 (4 a). The selected monitor data is converted to anapparatus monitoring signal 53 by an apparatus monitoring signalgeneration section 5 (5 a), and sent to a processing state comparingdecision section 19. At the same time, standard data of the monitor datataken out from a database 18 is also selected by a data selectionsection 4 (4 b). The selected standard data is converted to an apparatusmonitoring signal 52 by an apparatus monitoring signal generationsection 5 (5 b), and sent to the processing state comparing decisionsection 19 as a standard apparatus monitoring signal.

An example of a graph representing a comparison of these two signals isshown in FIG. 18. The processing state comparing decision section 19calculates a deviation of the apparatus monitoring signal 53 from theapparatus monitoring signal 52 in each lot, and generates comparisondata of respective lots as shown in FIG. 19. The processing statecomparing decision section 19 generates data and displays the data on adisplay section 7. When an apparatus monitoring signal is average dataor the like in a selected sample processing division, the comparisondata of the above described two signals can be obtained simply byderiving the difference between them. Furthermore, when the apparatusmonitoring signal holds temporal variation information in a selectedsample processing division, an area of a deviation between graphs oftemporal variation patterns of two signals can also be made comparisondata. Furthermore, as for the standard data, the semiconductormanufacturing apparatus maker may set the standard data in a databasepreviously, or monitor data obtained when a processing result was normalin past sample processing may be adopted. In addition, it is alsopossible to provide a threshold for the comparison result, and judgeconducted processing to be abnormal and issue a warning, when comparisondata has exceeded the threshold.

Furthermore, by using the above described database of the variationpattern of the standard apparatus monitoring signal, it is also possibleto detect a division among the sample processing divisions in that theprocessing is abnormal. Every some sample processing divisions, thesample processing divisions are arranged in decreasing order ofdeviation of a change of the apparatus monitoring signal from thestandard. By displaying this ranking, it is possible to indicate inwhich sample processing division during processing of one sample anabnormality has occurred.

FIG. 20 shows another embodiment of the sample processing apparatus 1according to the present invention. Operation of the sample processingapparatus 1 is nearly the same as that of the embodiment of FIG. 17except in that past apparatus monitoring signals are preserved in anapparatus monitoring signal database 20 instead of preserving themonitor data of past sample processing. As a result, the capacity of thedatabase can be reduced. For this purpose, past apparatus monitoringsignals preserved in the apparatus monitoring signal database 20 areloaded by an apparatus monitoring signal load section 62 under thecontrol of a controller 8, given to a processing state comparingdecision section 19, and compared with apparatus monitoring signalssupplied from an apparatus monitoring generation section 5.

In FIG. 21, another embodiment of the display screen of the displaysection 7 in the sample processing apparatus 1 of the present inventionis shown. The window 22 displays a variation of the processing statefrom wafer to wafer. The window 22 displays a graph with, for example,the abscissa indicating wafers finished in processing and arranged in atime series and the ordinate indicating the apparatus monitoring signalplotted for each wafer. A description 21 of an event that has occurredin the apparatus may be added to the window 22. As for this event, notonly an event that has occurred in the processing apparatus currentlyunder processing, but also an event that occurred in a semiconductormanufacturing apparatus that processed displayed wafers in the past maybe acquired by a LAN or the like and displayed. A button 24 displays amonitoring type of the apparatus monitoring signals currently displayedin the window 22. In addition, the button 24 may serve as a commandbutton for opening a monitoring type setting window. In the same way, abutton 25 displays the number of wafers displayed in the window 22. Inaddition, the button 25 is also a command button for opening a displaysample number setting window. A button 26 displays a device type, i.e.,a sample kind displayed in the window 22. In addition, the button 26 isalso a command button for opening a device type setting window. A button27 displays a sample processing division for generating the apparatusmonitoring signals to be displayed in the window 22. In addition, thebutton 27 is also a command button that opens a window for selecting thesample processing division.

In the embodiment of FIG. 21, a window 23 displays a variation of theprocessing state from lot to lot. The window 23 displays a graph with,for example, the abscissa indicating lots finished in processing andarranged in a time series and the ordinate indicating the apparatusmonitoring signal plotted for each lot. In manufacturing semiconductordevices, samples are processed by taking a cluster of several samplescalled lot as the unit.

In the case of 8-inch wafers, a cluster of twenty-five wafers is one lotin many cases. However, the number of samples included in one lotdiffers according to circumstances. Cleaning of the internal wall of theapparatus is conducted between samples in some cases. However, specialcleaning processing is conducted between lots in some cases.Furthermore, in an idle time between lots, the temperature of each placein the processing chamber might change. Even in such a situation thatsamples are processed stably, therefore, the apparatus monitoringsignals obtained by monitoring the sample processing do not become aconstant value. A constant pattern often repeats from lot to lot. Insuch a case, the conventional monitoring method of only determiningwhether the apparatus monitoring signals exists in a certain constantrange is insufficient.

In the present embodiment, an apparatus monitoring signal is comparedwith a variation pattern of a standard apparatus monitoring signalobtained during processing of a pertinent device and acquired from thedatabase. The comparison data is displayed as an apparatus monitoringsignal plotted from lot to lot. A lot that has had an abnormality inprocessing can be easily found. Furthermore, it is more desirable thatif a display portion of a lot is selected by a mouse or the likeapparatus monitoring signals of respective materials in that lot aredisplayed. In this case, when a lot that is considered to be abnormal isfound, selecting a display portion of this lot causes processing statesof samples belonging to the abnormal lot to be displayed in the window22. A sample included in the abnormal lot and subjected to abnormalprocessing can be easily found. Display in the window 23 can also becontrolled by using buttons 24′, 25′, 26′ and 27′ having functionssimilar to those of the window 22.

Furthermore, by using the above described database of the variationpattern of the standard apparatus monitoring signal, it is also possibleto detect a division among the sample processing divisions in that theprocessing is abnormal. Every some sample processing divisions, thesample processing divisions are arranged in decreasing order ofdeviation of a change of the apparatus monitoring signal from thestandard. By displaying this ranking, it is possible to indicate inwhich sample processing division during processing of one sample anabnormality has occurred.

In FIG. 22, another embodiment of the display screen of the displaysection 7 in the sample processing apparatus 1 of the present inventionis shown. FIG. 22 shows an example of a monitoring type selectionwindow. A monitoring type can be selected by using a menu 28. As forselection items of the menu 28, for example, “comprehensive level 1” isa monitoring type for displaying a rough processing state of theapparatus. “Comprehensive level 2” is a monitoring type of theprocessing state for monitoring a finer variation of the processingstate. “Comprehensive level 3” is a monitoring type for monitoring afurther finer variation. Besides, there may be an item of “processingperformance” relating to the working dimension precision and workingspeed. There may be an item of “part wear” for indicating the degree ofwear of parts in the apparatus. The check box 28 may be formed so that amultiplicity of kinds may be selected. In the case where a multiplicityof kinds have been selected, apparatus monitoring signals of amultiplicity of kinds are displayed in the window 22 and the window 23.Furthermore, a sample after sample display selection button 28′ and alot after lot display selection button 28′ may also be provided.

In FIG. 23, another embodiment of the display section 7 in the sampleprocessing apparatus 1 of the present invention is shown. FIG. 23 showsan example of a display sample number setting window. In the case ofdisplay conducted from sample to sample as in the window 22, the numberof display samples 29 can be selected. In the case of display conductedfrom lot to lot as in the window 23, the number of display lots 30 canbe selected.

In FIG. 24, another example of the display section 7 in the sampleprocessing apparatus 1 of the present invention is shown. FIG. 24 showsan example of a device selection window. A multiplicity of device kindsof displayed samples can be selected by using check boxes 31. On devicelabels 32 corresponding to the check boxes 31, device kinds are listed.For example, it is now assumed that a device name is “T12345F” and “T”and “F” in the device name have meanings concerning the devicestructure. In this case, it is desirable to be able to select not only“T12345F” as the display device name but also all device names beginningwith “T” or all device names ending with “F”. On the device labels 32,it is also made possible to select all of the same devices as the samplefinished in processing immediately before. When there are a multiplicityof kinds of recipes, i.e., combinations of processing conditions for thesame device, it is also permissible to recognize them as respectivelyseparate devices and allow device selection. Or a separate recipeselection window may also be prepared.

In FIG. 25, another embodiment of the display section 7 in the sampleprocessing apparatus 1 of the present invention is shown. FIG. 25 showsan example of a sample processing division selection window. By usingcheck boxes 33, a multiplicity of sample processing divisions to be usedfor generating the apparatus monitoring signals can be selected. From amultiplicity of sample processing divisions, one apparatus monitoringsignal may be generated and displayed. Or a multiplicity of apparatusmonitoring signals may be generated and displayed. On sample processingdivision labels 34 corresponding to the check boxes 33, sampleprocessing division names are displayed. Since the sample processingdivision name required to generate the apparatus monitoring signaldiffers depending upon the monitoring type, it is desirable that thesample processing division labels 34 differ according to the monitoringtype selected by using the pull-down menu 28.

In FIG. 26, another embodiment of the display section 7 in the sampleprocessing apparatus 1 of the present invention is shown. FIG. 26 showsanother example of the sample processing division selection window. Byspecifying a step start point 35 and a step end point 35′ on a time axis36, an arbitrary time range can be extracted as a sample processingdivision.

In FIG. 27, another embodiment of the display section 7 in the sampleprocessing apparatus 1 of the present invention is shown. FIG. 27 showsa system for automatically selecting an apparatus monitoring signal tobe displayed and a display method according to a use situation of theapparatus. For example, if a “process recipe development” button 37 ispressed, then an apparatus monitoring signal, such as a patterned shapepredicted value, required when developing a process recipe isautomatically selected and displayed. Furthermore, if an “afterapparatus cleaning” button 38 is pressed, then an apparatus monitoringsignal, such as an apparatus monitoring signal indicating residual gas,required after the apparatus cleaning is automatically displayed.Furthermore, if a “stable operation phase” button 39 is pressed, then amultiplicity of apparatus monitoring signals that indicate the degree ofwear of parts and patterned shape to be monitored during the stableoperation phase of the apparatus are displayed. Furthermore, if a“measure to counter failure” button 40 is pressed, then an apparatusmonitoring signal that reflects part engagement or the like of theapparatus is generated by an impedance monitor section or the like anddisplayed. Furthermore, a suitable event description portion 41 isdisplayed in a window 42 for each button.

In FIG. 28, another embodiment of the display section 7 in the sampleprocessing apparatus 1 of the present invention is shown. In theembodiments heretofore described, such as semiconductor manufacturingapparatuses using plasma, it is desirable to use as many sensors inquantity and kind as possible in order to accurately grasp theprocessing state of the apparatus. If the apparatus is monitored byusing a large number of sensors, then a large amount of monitor data aregenerated momentarily, and it is difficult to generate an apparatusmonitoring signal therefrom.

In this embodiment, therefore, there is effective a technique ofconverting a wide variety of monitor data acquired from the sensors 2 toa small number of effective signals 49 by using a signal filter 43,supplying the effective signals to a model expression section 45, andthereby obtaining an apparatus monitoring signal 44. It is usual that alarge number of model expressions have been prepared in the modelexpression section 45. According to a monitoring type set by amonitoring type setting section 11, a corresponding model expression isselected. By substituting the effective signals 49 into a selected modelexpression, the apparatus monitoring signal 44 is obtained. A signalfilter 43 for generating the effective signals to be substituted intothe model expression may differ according to the monitoring type. Thesignal filter 43 is acquired from a signal filter database 46 by asignal filter selection section 47 and used. Signal filters stored inthe signal filter database 46 may be preserved previously. Oreigenvectors obtained by analyzing the monitor data obtained whenprocessing has been completed normally, by use of a principal ingredientanalysis may be preserved in the signal filter database as a signalfilter. The principal ingredient analysis is a typical statisticalanalysis method capable of taking out an effective signal from a largenumber of signals in a descending order of importance.

In order to obtain the effective signals to be used in the modelexpression 45 for generating a certain apparatus state signal, it isalso possible to process a special processing setting combination,conduct a principal ingredient analysis, and regenerate a signal filterthat is optimum for the apparatus state at that time. The modelexpression 45 can also be obtained by conducting linear modeling, suchas the multiple regression analysis, between the apparatus performanceto be monitored, such as a value a deviation value of the patternedshape, and the effective signals 49. Or the model expression 45 can alsobe obtained by forecasting a function form of the model expression 45from a physical model of the processing and fitting the coefficientsthereof. By using the system of FIG. 28, a predicted value of a physicalquantity, such as the patterned shape of the sample, to be measuredafter the sample processing can be displayed immediately after thesample processing without measuring it. Early abnormality detection canbe conducted.

In FIG. 29, another embodiment of the display section 7 in the sampleprocessing apparatus 1 is shown. The monitoring and display methodheretofore described can be used for the apparatus control as well. Thisembodiment is a system for delivering apparatus monitoring signalsobtained by an apparatus monitoring signal generation section 5 to aprocessing performance prediction section 50, delivering a processingperformance predicted by the processing performance prediction section50 to a processing parameter modification quantity calculation section51, calculating a correction quantity of a processing parameter forremoving a deviation of a predicted value of the processing performancefrom a standard value, delivering the correction quantity to acontroller 3 of the semiconductor manufacturing apparatus, andcontrolling the processing condition of the next sample.

As already described, sample processing in the semiconductormanufacturing apparatus is repeated by taking a lot as the unit. It isalso possible to store the correction quantity and correct theprocessing condition of a sample in the same position of the next lot.When the kind of the device of the next lot is different, a correctionquantity conversion table between devices becomes necessary in somecases.

Another embodiment of the display section 7 in the sample processingapparatus 1 of the present invention will now be described. For example,a principal ingredient of an emission spectrum obtained by analyzing theprincipal ingredient of the emission spectrum during the waferprocessing can be used as a monitoring signal. At this time, someprincipal ingredients have correlation to quantities of respectivelydifferent reactive activated species. For monitoring process resultssuch as patterned shapes, therefore, it is necessary to monitorrelations among some principal ingredients. In the present embodiment,therefore, values of monitoring signals that indicate intensities of theprincipal ingredients of different emission spectra on the abscissa andordinate are displayed on the display screen of the display section 7 ina time series manner as a two-dimensional graph by the display settingcontroller 8, for example, in the configuration of FIG. 1. By thusdisplaying values of the monitoring signals for the principalingredients of different emission spectra as a two-dimensional graph ina time series manner, the process reproducibility can be confirmed fromthe locus of different monitoring signals.

For example, as shown in FIG. 30, a change of the value of a monitoringsignal “a” that indicates the intensity of a first principal ingredientand the value of a monitoring signal “b” that indicates the intensity ofa second principal ingredient during processing of one wafer is plottedat intervals of, for example, one second. The example of FIG. 30 showsthe case where processing of one wafer has been conducted normally. Inother words, at the time of normal wafer processing, the locus of themonitoring signals “a” and “b” lies nearly upon a locus indicated by •every wafer processing. On the other hand, in an example of FIG. 31, alocus 31 a of the monitoring signals “a” and “b” indicated by □ deviatesfrom a normal locus 31 n of the monitoring signals “a” and “b” indicatedby •. Therefore, the wafer processing indicated by the locus 31 a can bejudged to be abnormal. In this case, the time when an abnormality hasoccurred in processing can be identified on the basis of a point 31 m atwhich the locus 31 a of the monitoring signals “a” and “b” indicated by□ begins to deviate from the normal locus 31 n of the monitoring signals“a” and “b” indicated by •.

An example of FIG. 32 shows the case where processing of a multiplicityof wafers in one lot have been conducted normally. In other words, inthe case where all processing of a multiplicity of wafers in one lot isnormal, the locus of the monitoring signals “a” and “b” lies nearly upona locus indicated by • every lot. On the other hand, in an example ofFIG. 33, a locus 33 a of the monitoring signals “a” and “b” indicated by□ deviates at a point 33 m from a normal locus 33 n of the monitoringsignals “a” and “b” indicated by •. Therefore, the processing of amultiplicity of wafers in one lot indicated by the locus 33 a can bejudged to be abnormal in the processing of the wafer 33 m. A wafer inprocessing of which an abnormality has occurred can be thus identified.

The display section of each of the embodiments heretofore described maybe attached to the processing apparatus or may be mounted so as todisplay the information on a terminal installed in an office or a remotemonitoring company via a network. Especially, since apparatus monitoringdata is much smaller in size than monitor data in many cases, the loadon the network is light and apparatus monitoring data is optimum for usein remote diagnosis or the like.

Furthermore, these embodiments have been described mainly as tosemiconductor devices. However, a similar monitoring function can alsobe applied to manufacturing apparatuses and manufacturing methods ofother samples such as LCD devices.

According to the present invention, there is provided a section formonitoring the processing state of a sample processing apparatus havinga various complicated states due to processing conditions and theaccumulated number of processed samples, and acquiring apparatusmonitoring signals used to monitor the apparatus, from the variousprocessing sequences. As a result, it is possible to provide a processmonitoring device and its display method, a control method of a sampleprocessing apparatus, and a semiconductor device manufacturing methodthat can be easily operated.

Furthermore, according to the present invention, monitor data areacquired from the plasma device by using sensors, and apparatusmonitoring signals are generated from data of the most important sampleprocessing division concerning the sample processing performance. As aresult, it is possible to monitor the change of the processing stateaccurately and easily, and control the processing conditions.

1. A plasma processing method for processing a sample by using plasma ona lot unit basis, comprising: detecting plural kinds of information asmonitor data relating to a processing state of the sample, using aplurality of sensors; selecting a detection time range of the monitordata thus detected, which is used for monitoring a plasma processing;converting the monitor data within the selected detection time rangeinto a converted signal; predicting a pattern shape of the sample basedon the converted signal; calculating a correction quantity of aprocessing parameter, for decreasing a deviation between the predictedpattern shape and a standard value; storing the correction quantity ofthe processing parameter; and converting the correction quantity of aprocessing parameter obtained by the calculating operation when a kindof a next sample of a next lot is different from the sample, thereby touse a converted correction quantity of the processing parameter for aprocessing of the next sample.
 2. A plasma processing method forprocessing a sample by using plasma on a lot unit basis, comprising:detecting plural kinds of information as monitor data relating to aprocessing state of the sample, using a plurality of sensors; selectinga detection time range of the monitor data thus detected, which is usedfor monitoring a plasma processing; converting the monitor data withinthe selected detection time range, into a converted signal; predicting apattern shape of the sample based on the converted signal; calculating acorrection quantity of a processing parameter, for decreasing adeviation between the predicted pattern shape and a standard value; andstoring the correction quantity of the processing parameter, wherein acorrection quantity of a processing parameter obtained by thecalculating operation at a time of processing a sample at a position ofone lot is used for a processing of a sample at the same position of anext lot.